The present invention relates to a vacuum pump which comprises an inlet and an outlet, which are equipped with connecting devices for connecting lines.
Inasmuch as not high-vacuum pumps are affected which commonly are firmly joined by a pair of flanges having relatively large diameters to the chamber which is to be evacuated, the connection of the device which is to be evacuated to the inlet of a vacuum pump is provided by means of flexible lines which are connected releasably to the inlet of the vacuum pump. Also the outlet of a vacuum pump must generally be connectable to connecting lines, be it to discharge the pumped gases (in particular when these are aggressive or toxic) in a well controlled manner or in order to be able to connect the vacuum pump, in the instance of a high-vacuum pump, to a backing pump. In all instances, the connection for the connecting lines to the inlet or the outlet of the vacuum pump must be as leak-tight as possible so as to avoid the entry of leakage air or the ejection of detrimental gases.
It is known to employ, for the purpose of attaining a vacuum-tight connection of vacuum pumps with feed or passage lines, flange components (DE-A-24 16 808). At the location where the channel in the vacuum pump opens out at the surface of the casing there is commonly provided a connecting port with a flange. Also the line which needs to be connected the connecting port is equipped with a flange. The connection is provided in that the two flanges are placed on each other and arrested in this position with the aid of a clamping ring or other flange connecting components. Generally in the instance of this type of vacuum-tight connection, sealing rings of plastic, of rubber or also of metal are provided. These are located between the sealing faces in each case. With the aid of grooves, centering rings or alike they are maintained in their nominal position.
The risk of damaging the sealing faces at the protruding flanges is high. This also applies to the required space necessary to provide the flange connection, since both hands are needed to fit and affix a clamping ring or other flange connecting components.
It is the task of the present invention to render the geometrical arrangement of the leak-tight connection between a vacuum pump and a connecting line more user-friendly and more flexible.